The present invention relates to the fields of vascular and cardiovascular surgery, and more particularly to methods and devices for obtaining arterial or vascular occlusion when performing graft procedures.
Vascular and cardiovascular grafting procedures typically require the complete, or at least partial, occlusion of a selected vessel. For example, in the field of cardiovascular surgery, coronary artery bypass graft (CABG) procedures involving proximal anastomosis require the full, or at least partial, occlusion of the aorta. During proximal anastomosis, a vein or arterial graft is sewn to the aorta for revascularization of diseased or otherwise compromised coronary arteries. The internal mammary artery and radial artery of the arm are also used as bypass vessels. Occlusion of the aorta is typically accomplished by clamping. A variety of clamp configurations are in common use, including crossclamps for partial occlusion procedures. For procedures involving cardiopulmonary bypass, full aortic occlusion is required. Partial occlusion is used in either on or off-pump coronary artery bypass graft procedures for proximal anastomosis. Occlusion of the aorta prevents blood flow from entering the graft target site, creating a bloodless field for the surgeon to then sew the graft to the aorta. Once the graft is sewn to the aorta, the surgeon removes the clamp, once again allowing blood flow to the anastomotic region.
Unfortunately, injury resulting from such clamping can be significant. Such injuries include, but are not limited to, intimal hyperplasia, thrombosis (which may progress to total occlusion), embolism, intimal tears and flaps, mural dissections, aneurysms, arterial rupture, through-and through injury, and arterio-venous fistulae. As just one example, neurologic morbidity after cardiac surgery has been associated with particulate embolization. Crossclamp manipulation has been identified as the single most significant cause of particulate emboli release during cardiac surgery. Therefore, surgeons would prefer to eliminate the use of clamps during coronary artery bypass graft procedures in order to minimize adverse events and improve outcomes.
Efforts have been made to devise alternative devices and methods for performing bypass graft procedures that avoid complete clamping or crossclamping of the aorta. For example, U.S. Pat. No. 5,477,515 describes a bypass clamp with a spoon-shaped blade insertable through an incision in the aorta. Patches of saphaneous vein or other substitute are sutured on either side of the incision to reinforce the aorta and prevent tearing or abrasion by the clamp. U.S. Pat. No. 5,944,730 describes a device for creating a seal at an incision that includes a tube with a translatable shaft connected to a flexible inverting member. The inverting member is inserted into the incision and proximal force applied to the device creates a seal. Other methods have relied upon inflatable devices for partially occluding a vessel without interrupting blood flow. U.S. Pat. No. 6,143,015 describes such a device which includes first and second inflatable spaced apart members interconnected by a tubular connector that allows for blood flow.
Despite these efforts, there remains a need to provide for an anastomosis occlusion device that minimizes the adverse events associated with conventional clamping and crossclamping techniques, avoids trauma to the vessel and graft site, that is versatile and easy-to-use.